Below is the output stored in str variable, I want to extract the cardinality value of whatever it is, I have extracted it using simple way print str[15:18] but every time I have to change the string value if cardinality value going to increase or decrease.
Output:
{"cardinality":483,"timestamp":15369087280,"deltas":{"week_over_week":{"delta_fraction":0.047722318876,"last_week_value":146}}}
Stored in str:
str = response.text
Expected Output:
Active: 483
You can pass your string as JSON to get a dictionary, and then simply read out the value:
import json
s = '{"cardinality": 483, "timestamp": 15369087280, "deltas": {"week_over_week": {"delta_fraction": 0.047722318876, "last_week_value": 146}}}'
d = json.loads(s)
print(d['cardinality'])
# 483
print("Active Users:"),d['cardinality']Use ast:
>>> s='{"cardinality":483,"timestamp":15369087280,"deltas":{"week_over_week":{"delta_fraction":0.047722318876,"last_week_value":146}}}'
>>> import ast
>>> 'Active: %s'%ast.literal_eval(s)['cardinality']
'Active: 483'
>>>
As @101 said also able to use json.loads:
>>> import json
>>> s='{"cardinality":483,"timestamp":15369087280,"deltas":{"week_over_week":{"delta_fraction":0.047722318876,"last_week_value":146}}}'
>>> 'Active: %s'%json.loads(s)['cardinality']
'Active: 483'
>>>
There are 2 ways :
1.
In [10]: import ast
In [11]: s='{"cardinality":483,"timestamp":15369087280,"deltas":{"week_over_week":{"delta_fraction":0.047722318876,"last_week_value":146}}}'
In [12]: ast.literal_eval(s)
In [13]: %timeit ast.literal_eval(s)['cardinality']
10000 loops, best of 3: 29.4 µs per loop
2.
In [14]: import json
In [15]: s='{"cardinality":483,"timestamp":15369087280,"deltas":{"week_over_week":{"delta_fraction":0.047722318876,"last_week_value":146}}}'
In [16]: %timeit json.loads(s)['cardinality']
100000 loops, best of 3: 5.73 µs per loop
So you should use json as its relatively faster than ast
json.loads()orast.literal_eval()to deserialize it to a python dict, then you just have to get the value from the"cardinality"key.requestslibrary ?